Meaning

noun a popular programming language that is relatively easy to learn; an acronym for beginner's all-purpose symbolic instruction code; no longer in general use

noun (usually plural) a necessary commodity for which demand is constant

adjective pertaining to or constituting a base or basis

originAcronym for Beginner's All-purpose Symbolic Instruction Code, but designed to spell out basic (i.e. simplistic). First use appears c. 1964 in the BASIC Instruction Manual.

Etymology from Wiktionary, CC BY-SA 3.0